By using these parameters, the GW spectrum from first-order phase transition could be estimated.
There are three sources of GW spectrum: bubble collision [1]}, plasma turbulence [2]}, and compression wave of plasma [3]}.
The spectra could be calculated by the details of bubble dynamics, and the fitting formulas of them are provided in Ref. [3]}.
In our analysis, we will focus on the GW spectrum from compression wave of plasma, which typically is the largest contribution among them.
The formula from the compression wave of plasma [3]} is given by
\(\Omega _{\rm comp} (f) h^2=\widetilde{\Omega }_{\rm comp} h^2 \times (f/\tilde{f}_{\rm comp})^3\left(\frac{7}{4+3(f/\tilde{f}_{\rm comp})^2}\right)^{7/2},\) 
